factory_test_tools: fix vblock test code

The example test code is currently simply for reference and not used by anyone.
However, to prevent confusion, here's the fix.

BUG=none
TEST=dump_fmap -x bios.bin
     python vblock.py VBLOCK_A
     # seeing correct info dumps

Change-Id: I87b91e266015f957ac7f79cc5a43a7b43257cacd
Reviewed-on: http://gerrit.chromium.org/gerrit/3995
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
1 file changed